#include <stdio.h>

void change(int* a,int* b){
		int z = *a;
		*a = *b;
		*b = z;
	}
void swap(int** pi,int** pj){
		int temp = **pi;
		**pi = **pj;
		**pj = temp;
	}
int main (){
		int x = 10,y = 20;
		//change(&x,&y);
		int* pa = &x;
		int* pb = &y;
		swap(&pa,&pb);
		printf("x=%d y=%d\n",x,y);
	}
